Two fatal traffic accidents Friday and Saturday involving trucks with faulty brakes have prompted truck-safety advocates to question current inspection standards in Maryland.

"The bigger numbers of accidents that I'm aware of are coming from improper maintenance," said Sally Murphy, a Ruxton woman who founded Citizens Against Negligent Trucking two years ago.

Murphy, who was critically injured in 1987 when a tractor-trailer with a bad tire smashed into her car, said the current program calls for trucking firms to self-inspect every 25,000 miles or once a year, whichever comes first.

"There are some companies that do an excellent job" with the self-inspection program, Murphy said.

But not all trucking firms are complying, and random inspection crackdowns by local and state police are sometimes thwarted by truckers warning other truckers on their CB radios, Murphy said.

State Sen. Ida Ruben, D-Montgomery, thinks the current system of truck inspections should be more strict. Since 1987, she has sponsored a bill calling for annual, mandatory truck inspections but the measure has never made it out of committee.

"The police have done a marvelous job with making random inspections," Ruben said. "But there's not enough resources to do all the inspections."

Friday in Howard County, Jeffrey James Baldwin, 23, of Lanham, died after being run over by the back wheels of his dump truck.

Baldwin apparently had jumped from the cab after the truck's brakes failed while he was driving westbound on Md. 32 near Columbia, said Howard County police officer Tom Glorioso.

About 4:20 p.m. Saturday on the southbound Harbor Tunnel Thruway, less than a mile from the mouth of the Harbor Tunnel, the brakes failed on a dump truck carrying 22 tons of asphalt, according to Maryland Toll Facilities Police. The driver lost control, bounced against the jersey wall, then careened back into traffic, driving over the top of Kimberly Ann Schroeder's 1988 Nissan Sentra, crushing it, police said.

Schroeder, 23, an airline reservation clerk who lived in the 7400 block of Kirtley Road in Eastpoint, died at 12:30 a.m. yesterday at the Shock-Trauma Unit in Baltimore of massive head injuries. Schroeder was planning to be married this summer.

It took rescue workers more than an hour to cut her out of the wreckage of her car. A huge crane had to be brought in to lift the dump truck off of it.

That fatal collision set off a chain-reaction accident involving nine other vehicles, said Cpl. Lee O. Palmer of the Toll Facilities Police.

"It's been quite some time since we've had an accident as bad as this," Palmer said.

Eight other people were injured in the accident, none seriously, Palmer said.

"I used to worry about her a lot," Patricia Schroeder, Kimberly's mother, said yesterday, hours after her daughter died, "because working for America West Airlines, she flew a lot. I never thought something like this would happen."

Palmer said that Saturday night, Toll Facilities Police inspectors examined the dump truck, which is owned by Cunningham Paving Co. Inc. of Crownsville. They found that three of the four brakes were out of alignment, that one brake line was dry-rotted and cracked, that the truck's odometer didn't work and that the vehicle was 2,900 pounds over the legal weight.

"Charges will be filed," Palmer said. Police were waiting to confer late today with the city state's attorney's office before deciding on exactly what those charges should be.

A spokeswoman for Cunningham today described company officials as "emotionally distraught" over the accident and said they would have no public comment.

The driver of the dump truck, John Willie Buie, 58, of Baltimore, was unhurt in the accident. He was issued one traffic citation for operating an overweight vehicle, and another for operating a vehicle with defective brakes. The potential fines total $660, said Thomas Freberger, a spokesman for the Maryland Toll Facilities Department.

The truck was the second owned by the Crownsville paving company to have had brake failure Saturday. Another of its trucks had to be towed from the tunnel earlier in the day when its brakes locked, Freberger said.